


Knot me not

by Bill_Longbow



Category: Captain America (Movies), Iron Man (Movies), Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Alpha!Steve, Alpha!Tony, Alpha/Beta/Omega Dynamics, Armor Kink, Armor Porn, Established Relationship, Knotting, M/M, Masturbation in Shower, Not Canon Compliant, Rutting
Language: English
Status: Completed
Published: 2020-05-02
Updated: 2020-05-02
Packaged: 2021-03-02 03:53:34
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,090
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23958739
Author URL: https://archiveofourown.org/users/Bill_Longbow/pseuds/Bill_Longbow
Summary: When their omega is away on a black-out mission, alpha Steve and alpha Tony resort to using the armour as a very fancy fleshlight when Steve goes into rut.
Relationships: Background James "Bucky" Barnes/Steve Rogers/Tony Stark, Steve Rogers/Tony Stark
Comments: 37
Kudos: 194
Collections: Marvel Trumps Hate 2019





	Knot me not

**Author's Note:**

  * For [sabrecmc](https://archiveofourown.org/users/sabrecmc/gifts).



> A fill for Sabre's generous donation to my Marvel Trumps Hate armour porn offer.
> 
> I deliberately say _a_ fill, because there's two more in progress, since there just isn't enough armour porn in the world!
> 
> Thank you to [PinkGoldAngel](https://archiveofourown.org/users/PinkGold/) for fleshing out this idea I had, to LadyIronWinter for cheering and to Kieran_is_hiding for betaing!

He lets the shield fly as hard as he can throw it, and catches it on the rebound after it decapitates no less than seven of the bug-like grunts and cuts one clean in half. The thud when he catches it reverberates through his entire torso, and he knows only Tony's reinforced gloves are what makes sure he still has a hand to throw with again. 

He runs straight into another group, punching and kicking hard enough to make the bugs go sprawling, using the shield as a battering ram. The sounds of battle around him are so loud they drown out his thoughts, his sense of time, his sense of self. Nothing exists but the next enemy ahead, nothing else matters to him but to punch, duck, kick, throw. 

He's breathing hard, muscles finally burning with the exertion, but it barely registers. Nothing registers when he's like this. His teammates' voices are a soft burr in the background, the screeching of the bugs as they are slain barely audible above the rush of blood in his ears. Punch, duck, kick, throw. 

“Leave a few alive, Cap,” someone jokes over the comms, but he pays them no heed. He can’t stop now, he has too much energy, feels too much urgency... he needs to _kill._

Something flies overhead, bombing a group of bugs in Steve’s path, but instead of advancing on the next group Steve suddenly halts to sniff the air. It’s faint, but undeniable: Tony’s smell drifts over the battlefield, and Steve growls, running at the nearest bugs to crush them. He fights even more viciously than before. _He needs to get to Tony._

His arms hurt and his chest is heaving when he suddenly realizes there is no next enemy to _punch-kick-throw._ As he stands catching his breath, Tony lands a little way away from him to survey the carnage around them.

Steve advances on the armour but halts when the faceplate retracts, suddenly overwhelmed by the scent of his mate _protect-mine-safe_ , and he whines, leaping the final eight feet that separates them. 

"Woah, big guy," Tony mutters -- keeping upright despite the force of the impact -- but Steve barely registers as he pushes his nose in the crook of Tony's neck, whining again when the shoulder plate doesn't give him enough space to do so. 

"It's that time, huh?" Tony says quietly, and wraps his arms around Steve's shoulders while the armour bleeds back into the particle housing on Tony's chest. 

That show of trust leaves Steve overwhelmed, and he feels his eyes water as he pushes closer to his lover. "Sorry," he whispers, which makes Tony try and pull back -- probably to cup Steve's face or some other romantic gesture like that -- but Steve holds on tight. Without the armour Tony is no match for Steve's strength, alpha or not, and Steve relaxes a little when Tony hugs him again and pets his hair. 

"No apologies, this is just biology. Sucky timing biology, but that's not your fault."

Steve nods miserably. Sucky timing indeed, with their omega on a black-out mission on a different continent. Steve rubs himself against Tony's hips involuntarily. His lover smells too good, like _home_ _,_ and another whine escapes him.

“Fly you home?”

Steve pulls back. The offer shakes off a little more of the fog that came over him on the battlefield, and which only lifted a little at the smell of Tony. He smiles, grateful for Tony’s consideration. The last thing Steve needs right now is an endless debrief, though he knows the other alphas will back down when they smell him. Maybe he _should_ do the debrief, just for that satisfaction.

He steps back far enough for the armour to envelope Tony again, but his lover keeps the faceplate off, and Steve steps forward, hugging the armour tight while pushing his nose in the crook of Tony’s neck. He barely registers them lifting off, until the wind is tugging at his hair and he realizes he’s dry humping the armour. He tries to hold still, because he doesn’t want to make the headlines like this, but it’s hard.

The flight couldn’t have taken more than twenty minutes, but it might’ve been hours or days. When they finally land on their private platform next to the penthouse, Steve feels like he's bursting out of his skin. He’s running even hotter than usual, and his armour chafes on his skin. He has trouble making his arms let go of Tony’s shoulders when their feet hit the landing pad. The metal of the armour feels cool and safe against his feverish skin, and the way it follows Tony’s form never fails to rile Steve up.

“Come on, big guy, let’s get you settled.” Tony’s voice is gentle and sweet because his lover knows any hint of challenge can set Steve off at this point. It’s one thing about the serum he hasn’t come to grips with, but when the doors to the balcony slide open to reveal Bucky’s lingering scent Steve sags and whines, and lets himself be herded inside. 

As soon as the doors close behind them Steve halts and pulls Tony close to him again. He’s grateful his alpha lover doesn’t mind him being this clingy when he gets close to a rut, but the other times this happened Bucky was there to provide relief. Their omega's hole slick and welcoming, able to withstand anything Steve had to give-- no, _greedy_ for it, pushing back against Steve’s cock, clenching around him…

“ _Steve_ ,” Tony sighs fondly, cradling him close as Steve ruts against his hip. His scent is what tips Steve over the edge, _love-safe-home_ , and his whole body jerks as he comes in his pants like a teenager.

Tony holds him close all through, his scent slightly changing, arousal intermingling. Steve’s knot is painful now, straining against the coarse fabric of his under armour and he fumbles with the release of his pants to get them off. 

“Here, let me,” Tony offers without prompting, and opens Steve’s pants far enough for the strain on his knot to subside a bit, but then he stops and takes Steve’s hand instead.

“Shower or bed?” 

Steve doesn’t care one whit as long as he can bury his cock somewhere warm and welcoming, but he knows Tony is trying his best to take on a role that goes against his nature, so Steve whispers “shower.”

Bucky would’ve known what to do. He always did. Something about their scent that only their super sensitive omega picked up. He would’ve prepared a nest and ordered Steve into the shower, would’ve welcomed Steve with his mouth and ass… 

“Shower it is. J, shut the penthouse down. Priapus protocol, you know the drill.”

“Certainly, Sir.”

Steve feels a little less… on edge knowing their home is now virtually impenetrable, but just thinking about their omega out on his own, God knows where, makes him shiver and feel nauseous with the need to protect and claim. Intellectualy, he knows this is ridiculous. If anyone is capable of handling _anything_ , it’s Bucky, but his hormones are all over the place during rut and his mood swings from confident to extremely worried. 

He follows Tony through their living space to the bedroom and the adjacent bathroom. Bucky’s smell lingers stronger here, and it’s enough to help him relax a bit more as Tony unbuckles the straps of his uniform and strips him.

"Don't go," Steve pleads when Tony gently nudges him towards where Jarvis has started the shower, grabbing Tony's hand. His cock is still rock hard, but his knot has sunk without a hole to accommodate it and push against, and his orgasm has done nothing to alleviate his burning need.

Tony’s smile turns a little wicked, and without answering he makes his clothes melt away like he did the armour. 

“ _Tony,_ ” Steve sighs, relieved he finally gets to feel his lover, and he pulls Tony closer. “Wasn’t there a rule about not wearing nanites as clothing?” he asks, smiling against the skin of Tony’s neck. 

“That _rule_ was invented solely so that you two can rip my poor Tom Fords to pieces, Conan.” 

Tony pulls Steve towards the shower without breaking the hug, and Steve awkwardly shuffles with him until the spray hits his head and he sighs in relief. He’s content to stay standing with his eyes closed as Tony washes the grime of battle from his hair and skin. Tony’s hands are gentle, going over Steve’s body with the method and care only a lover can, and the touches reignite Steve’s lust, stronger than before.

He startles when Tony wraps a hand around his aching cock and he throws out a hand against the wall to steady himself. 

He bucks into the touch when Tony starts to stroke up and down. Tony’s grip is a little tighter than Steve’s own fist, but it’s not enough, not even when Tony rubs his thumb over the head and cups Steve's balls in his other hand. 

_“I need more, Tony, I need…_ ” Steve trails off, hips jerking as he fucks Tony’s fist and comes despite his claims, shooting white ribbons all over the shower tiles. 

“I know, lover,” Tony sighs and softly kisses Steve’s cheek before pulling back. “But no way is _that_ ,” he waves at where Steve’s knot has formed ineffectually again -- more than doubling the girth of his cock -- “coming near my ass.”

Steve nods miserably. He knows. He would hurt Tony if they tried, and there isn’t a single place in the multiverse where he would willingly do that. He fingers the casing of the nano-particles sitting proud on Tony’s chest where the arc reactor used to be and waits for his knot to subside.

“Rogers, you’re a genius. Man with a plan indeed.” Tony suddenly straightens, an excited gleam in his eyes.

“I am?” Confusion makes his arousal dampen a little as he catches the towel Tony throws at him. It’s not unusual for Tony’s brain to go off on a tangent after -- or even during -- sex, but he has never called Steve a genius before.

“You’ll see, come on, come on!” 

Steve smiles despite himself at Tony's enthusiasm and sits down where Tony pats on the bed.

He turns to watch Tony who spreads himself luxuriously on the bed with a ridiculous wiggle of his eyebrows. 

"But Tony, you just said…"

"Ah ah ah, patience, Sheriff Woody," Tony tuts. 

From the nano-casing the armour starts to form and Steve frowns, uncomprehending, until he sees the armour doesn't envelop Tony, but forms next to him. Tony has closed his eyes in concentration as the nanites ripple and shimmer, creating a full body-sized armour in-between them on the bed. 

Tony opens his eyes when the nanites form two perfectly shiny red feet and grins. 

"Tadaa!" His jazz hands are copied by the armour next to him, creating a weird comedic effect that startles a laugh out of Steve. 

"Wow," he smiles, receiving a satisfied grin in return. 

"You haven't seen the best part yet," Tony says huskily and slowly the armour rolls to its stomach, and Steve watches mesmerized as it lifts its ass. 

"Don't be shy, Steven,” Tony teases, making the armour wiggle its butt. 

It’s a gift Steve doesn’t want to waste, so he rolls to his knees in one fluid movement, until he’s sitting behind the armour. He tentatively reaches out to put his hand on the smooth surface of its hip. He’s always had a thing for the armour, how could he not? It’s more than a show of Tony’s sheer brilliance, it’s _gorgeous_ , but he never touched it like this before. 

When he touches the metal Tony makes the armour push back against his hand in a movement that reminds him so much of Bucky it makes his heart clench in sudden homesickness.

“Tony,” Steve sighs and briefly looks at his lover, who sits up with a concerned frown, studying Steve's features. He runs a steadying hand through Steve’s hair and he leans into the touch. 

“I know, honey, I miss him too.” 

Steve’s grateful Tony doesn’t try to comfort him with empty phrases or promises he can’t keep. They don’t know when Bucky will return, and they have to make the best of it together. He opens his eyes to smile at his lover, and pulls him closer for a kiss. “We’re doing alright, aren’t we?”

Tony’s answering smile is beautiful and cheeky, and smells like adventure. “We could be doing better than just alright,” he smirks and pats the ass of the armour. 

“Never quickly satisfied, are you?” Steve grins and squeezes Tony’s shoulder. 

“Look who’s talking.” Tony flicks the head of Steve’s cock which is already straining and purple again. “Come on, Captain,” he challenges as he raises onto his knees to lean closer to Steve. “ _Knot_ me.”

Steve growls and pounces, pushing Tony against the mattress and plundering his mouth as he holds him down with an arm over his ribs. Alpha or not, Tony is no match against Steve’s strength, but that doesn’t mean he doesn’t try, and the struggling gets Steve’s blood up even more. 

Suddenly there are arms around his waist, lifting him off Tony with an iron grip, and he turns his head to snarl at the intruder, startled when he encounters the impersonal mask of the armour. 

Tony hugs him from behind when the armour lets him go, but the challenge is gone from his smell, and it helps to soothe Steve, if only a little. The armour bares its neck, and it would be a parody if it wasn’t so god damned gorgeous. Steve knows the armour is as much part of Tony as his limbs are, and knows this is another show of Tony’s love for him.

“Steve,” Tony sighs and rubs his cheek against the back of Steve’s jaw. “Close your eyes.”  
  
Even in his current state Steve can’t deny Tony anything, so he squeezes his eyes shut, and gasps when Tony wraps a calloused hand around the base of his dick. He bucks into the touch involuntarily, but Tony doesn’t seem to mind when he kisses the side of Steve’s neck lovingly.

Rustling in front of him tells Steve the armour is moving, but he manages to keep his eyes closed. The trust in their unusual relationship runs both ways. He knows it’s coming, but the cold metal pushing against the tip of his dick still startles him. He flinches a little, but Tony soothes him, radiating nothing but love and trust. Tony guides his cock in between what must be the armour’s ass cheeks, but instead of unresisting metal there’s space to push his cock into, feeling smooth and wet.

Without opening his eyes, Steve moves his hands to the armour’s hips and uses the leverage to push himself inside. It’s nothing like fucking into a human, but it still feels so overwhelmingly good to finally be able to bury himself into _something_ that he comes after only a single thrust.

His come slicks up the inside even more, and Steve has no clue how Tony does it, but the walls of the armour shift and adjust around the girth of his dick when his knot fills to its fullest.

“Nah ah, not yet you don’t,” Tony whispers and suddenly the pressure against his knot disappears, leaving Steve reeling, and he opens his eyes to glare at Tony.

“You call that fucking?” Tony goads him, and Steve knows what Tony is doing, but dammit it still works. “My grandma had better stamina than that,” Tony continues, scraping his teeth over Steve’s neck glands. “Only the _best_ can knot my armour, the _strongest_.” 

Steve can smell Tony’s arousal now, feels the challenge that comes with it deep within his core, and he holds the armour's hips tight enough to slightly dent the metal, growling low in his throat. _His._

"You're like a pup on his first rut," Tony jeers and Steve sees red. He's aware that he snarls at Tony and he pushes him to the side, but it's like the mist of battle came over him again. In the same movement he pulls the hips that he's still holding onto closer and pushes inside. 

It feels even better this time around. He pulls the armour- he's vaguely aware it's not a real ass, knows he doesn't have to be careful -- as close against his stomach as he can, burying himself completely. 

It feels better, but it's not _enough_. After three orgasms he's finally at the point where he doesn't go off like a rocket as soon as someone touches his cock, so he pulls back and slams into the armour with force. And again and again and again. Each thrust punches a moan out of him, with each thrust he pushes in as far as he can, moving faster and faster as he fucks the armour with abandon. 

It's so sleek and beautiful and even if it isn't really, it's still _Tony_ , with his smell and his curves. Never before has Steve dared to let go completely, always on some level aware of his strength. But as his muscles tighten and he edges closer and closer to completion he lets go of his reserves and grips as tight as he can, letting the alpha in him run the show. 

A stuttered intake of breath followed by a moan and the smell of Tony’s come filter into Steve’s consciousness. It’s the realization Tony came from watching him sends Steve cascading over the edge a fourth time. He comes violently, his body squeezing every last drop of come out as he shudders and moans. 

“That was so fucking hot,” Tony whispers.

Steve slumps forward, panting against the armour’s back when his knot starts to form. This time Tony doesn’t interfere, and his knot swells and swells until it’s squeezed snug in the hole he just ravaged. He whines when the metal against his cheek melts away, but sighs contentedly when Tony shimmies in its place, hugging Steve close to his chest.

It’s a bit awkward, with the lump of metal encasing Steve’s dick in between them, but Steve supposes it’s not much different from the fleshlights they used to use, way before they found Bucky and pulled him into their relationship.

“ _You_ are the hottest alpha I know,” Tony says fondly, running gentle fingers over Steve’s scalp.

“You’re not so bad yourself,” Steve answers, smiling against the skin of Tony’s chest. 

**Author's Note:**

> This is my 100th posted fic! 
> 
> To celebrate I want to do a little give away, so if you'd like to see me write a prompt you can either give me one in the comments, or join us on the 16+ [ Stuckony discord server ](https://discord.gg/jtXcc3n) for all things Tony, Bucky and Steve! Prompts can be any rating, but must concern stuckony or any of the sub pairings, and can be submitted until Saturday May 9th.
> 
> This is also my first published a/b/o verse fic, let me know what you think!


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